When a mobile phone is used, voltage of a mobile phone battery needs to be monitored in real time. There is generally a graphic indicator for the voltage or quantity of electricity of the battery on an interface of the mobile phone, and a user can judge a current status of the battery according to the indication icon. Moreover, it is necessary to give the user an alarm or a power-off prompt in a case of low voltage of the battery.
At present, a manner of Analog-Digital (A/D) conversion is generally used for detection on the circuit, specifically comprising: the voltage of the battery is firstly input to an A/D conversion module to be converted into a digital quantity and then transferred, by a system bus, to a mobile phone baseband module to be processed by software; and the software judges the range of the voltage of the battery by table lookup or comparison and then refreshes the icon on the interface according to the judgment result.
FIG. 1 is a block diagram of a common method for implementing a grading indicating circuit for the voltage of the battery. As shown in FIG. 1, the grading indicating circuit for the voltage of the battery is implemented by A/D conversion, and ADC in FIG. 1 represents an A/D converter.
In implementation, the defects of the above method lie in: the current voltage value of the battery needs to be acquired by continuous query of the software, a time interval for each query is variable, and the query needs to be controlled by a processor thereby consuming resources of the processor; in addition, various errors are easy to be introduced as the A/D conversion needs the cooperation of a clock, therefore, it is necessary to calibrate the voltage of the battery of each mobile phone in a later period.